[libvirt] [PATCH 2/7] qemu: Abstract code for memory controller setting into a helper

[Daniel P. Berrange]

On Fri, May 17, 2013 at 07:59:32PM +0800, Osier Yang wrote:
> ---
>  src/qemu/qemu_cgroup.c | 120 ++++++++++++++++++++++++++++---------------------
>  1 file changed, 68 insertions(+), 52 deletions(-)
> 
> diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
> index 0c4792e..2751be0 100644
> --- a/src/qemu/qemu_cgroup.c
> +++ b/src/qemu/qemu_cgroup.c
> @@ -455,6 +455,72 @@ qemuSetupBlkioCgroup(virDomainObjPtr vm)
>      return 0;
>  }
>  

My email client is showing trailing whitespace here. Not sure
if that is genuine or not. Also 2 blank lines between functions

> +static int
> +qemuSetupMemoryCgroup(virDomainObjPtr vm) {

Put the '{' on a new line as you did with previous patches

> +    qemuDomainObjPrivatePtr priv = vm->privateData;
> +    unsigned long long hard_limit;
> +    int rc;
> +    int i;
> +
> +    if (!virCgroupHasController(priv->cgroup,VIR_CGROUP_CONTROLLER_MEMORY)) {
> +        if (vm->def->mem.hard_limit != 0 ||
> +            vm->def->mem.soft_limit != 0 ||
> +            vm->def->mem.swap_hard_limit != 0) {
> +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                           _("Memory cgroup is not available on this host"));
> +            return -1;
> +        } else {
> +            VIR_WARN("Could not autoset a RSS limit for domain %s", vm->def->name);
> +            return 0;
> +        }

Not sure why we need this VIR_WARN at all. If no limits are set in the XML,
then we should not warn about a missing feature that we don't actually
need.


> @@ -668,58 +734,8 @@ int qemuSetupCgroup(virQEMUDriverPtr driver,
>      if (qemuSetupBlkioCgroup(vm) < 0)
>          goto cleanup;
>  
> -    if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_MEMORY)) {
> -        unsigned long long hard_limit = vm->def->mem.hard_limit;
> -
> -        if (!hard_limit) {
> -            /* If there is no hard_limit set, set a reasonable one to avoid
> -             * system thrashing caused by exploited qemu.  A 'reasonable
> -             * limit' has been chosen:
> -             *     (1 + k) * (domain memory + total video memory) + (32MB for
> -             *     cache per each disk) + F
> -             * where k = 0.5 and F = 200MB.  The cache for disks is important as
> -             * kernel cache on the host side counts into the RSS limit. */
> -            hard_limit = vm->def->mem.max_balloon;
> -            for (i = 0; i < vm->def->nvideos; i++)
> -                hard_limit += vm->def->videos[i]->vram;
> -            hard_limit = hard_limit * 1.5 + 204800;
> -            hard_limit += vm->def->ndisks * 32768;
> -        }
> -
> -        rc = virCgroupSetMemoryHardLimit(priv->cgroup, hard_limit);
> -        if (rc != 0) {
> -            virReportSystemError(-rc,
> -                                 _("Unable to set memory hard limit for domain %s"),
> -                                 vm->def->name);
> -            goto cleanup;
> -        }
> -        if (vm->def->mem.soft_limit != 0) {
> -            rc = virCgroupSetMemorySoftLimit(priv->cgroup, vm->def->mem.soft_limit);
> -            if (rc != 0) {
> -                virReportSystemError(-rc,
> -                                     _("Unable to set memory soft limit for domain %s"),
> -                                     vm->def->name);
> -                goto cleanup;
> -            }
> -        }
> -
> -        if (vm->def->mem.swap_hard_limit != 0) {
> -            rc = virCgroupSetMemSwapHardLimit(priv->cgroup, vm->def->mem.swap_hard_limit);
> -            if (rc != 0) {
> -                virReportSystemError(-rc,
> -                                     _("Unable to set swap hard limit for domain %s"),
> -                                     vm->def->name);
> -                goto cleanup;
> -            }
> -        }
> -    } else if (vm->def->mem.hard_limit != 0 ||
> -               vm->def->mem.soft_limit != 0 ||
> -               vm->def->mem.swap_hard_limit != 0) {
> -        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> -                       _("Memory cgroup is not available on this host"));
> -    } else {
> -        VIR_WARN("Could not autoset a RSS limit for domain %s", vm->def->name);
> -    }
> +    if (qemuSetupMemoryCgroup(vm) < 0)
> +        goto cleanup;

ACK with warning removed


Daniel
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